JP2002233857A - Method for detoxicating all of pcb-containing insulating oil in transformer, etc. - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct the unreality of the conventional measure to carry out the whole cleaning step starting from breaking/crushing of a transformer, etc., inside a supercritical fluid circulating route for preventing PCB from scattering and PCB gas from escaping. SOLUTION: The transformer, etc., from which PCB-containing insulating oil is withdrawn is crushed, cleaned and sorted into metal, an insulator 18, paper, a fiber 19, oil content and water in the water of a water tank 13 installed in an airtight chamber shut off completely from the air outside. The PCB contained in the sorted paper and fiber 19 is extracted by an extraction system 27 to use a solvent CO2 in the supercritical fluid circulating pipeline. The withdrawn PCB-containing insulating oil collected in the above step is decomposed into water, carbon oxide and hydrochloric acid by a supercritical hydroxylation reaction system 53 to add an oxidizing agent in the supercritical fluid circulating route.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PCB for a transformer or the like.
The present invention relates to a method for detoxifying the total amount of insulating oil contained.

[0002]

2. Description of the Related Art PCBs are present without being destroyed even in a very small amount, and congregate at both poles due to the rotation of the earth and contaminate rivers and seas, as well as reindeer, seals, seals, etc., which accumulate especially in animal fat. From small fish to medium and large fish, and finally to humans, they accumulate in the body through the food chain, which has a great impact.

[0003] Incidentally, in the Asahi Shimbun on January 29, 2000, "Japanese dioxin intake is about 6%.
PCB (polychlorinated biphenyl) whose use was banned about 30 years ago as a source of coplanar PCBs
Occupy a large proportion and has not decreased recently, according to a study by Professor Shigeki Masunaga (Environmental Chemistry) at Yokohama National University. It has been pointed out that PCBs have been lost or leaked due to poor management, but there is a need for vigilance as a source of dioxins by incineration.

[0004] The highly toxic coplanar PCB is produced by incineration of garbage and used as an insulating material for industrial products.
B, and these two sources are expected to dominate.

It is required to complete the detoxification of the stored PCB as soon as possible.
In June 2000, the governor of Tokyo declared to dispose of items in storage in Tokyo, but the solution has not been determined.

[0006] In other words, in Japan, in the Environment and Safety Division of the Environment Insurance Department of the Environment Agency, the “Study Committee for Promoting the Treatment of Equipment Contaminated with PCBs” and the Masayoshi Hiraoka, a professor emeritus of Kyoto University, as a leader, the Working Group on the Examination of PCB Processing, etc. And the Working Group on Examination of Standards for PCB Treatment Measures have been organized and promoted.
In the two-year interim report, it has been pointed out that a safe treatment method for PCB-contained equipment (transformer / transformer) members with a treatment reference value of 0.5 ppm or less has not been determined.

On the other hand, according to the results of a survey conducted by the Ministry of Health and Welfare in 1994 published in 1993, 7% of high-voltage transformers and capacitors were found to be based on the ledger of the Japan Electrical Insulators Processing Association. However, 4% of the weight of the pressure-sensitive copy paper that was confirmed to be stored in the Ministry of Health and Welfare's storage survey in 1986
, Respectively, are unknown or lost. In a company, there is a risk of loss or improper disposal due to lack of information transmission due to business closure, bankruptcy or transfer of personnel, and PCBs are released to the environment due to deterioration of storage facilities, leakage due to earthquakes and accidents, etc. I can't wipe it out.

If strict storage of waste PCBs and the like is to be continued in the future, great care must be taken to minimize leakage to the environment. Personnel responsibility, facility storage and maintenance responsibility, The burden of maintenance and repairs is a great burden and must be paid semipermanently. This is a considerable cost for society as a whole. In addition, the number of PCBs currently in use is twice as large as the amount of storage, so that it is necessary to store them one after another, and it is expected that storage and maintenance will be more difficult for small and medium-sized businesses and the like.
In addition, keeping them unresolved for 30 years and keeping the outlook unclear will push the cleanup of what has been manufactured and used to our generation to the next generation, and responsibility between generations You must also consider solemnly that it will be passed on.

In addition, as a result of these regulations and guidance, waste PCB, waste oil containing PCB and PCB contaminants were designated as specially controlled industrial waste based on the Waste Management Law in 1992,
High temperature incineration or solvent cleaning was specified for the treatment of containers after extracting PCB-containing oil from transformers, etc. It is socially difficult to obtain an agreement, and even after washing, the used washing solvent becomes waste PCB, etc., and a facility to completely treat this (high-temperature incineration) is now available to local residents. No treatment of PCB-contaminated containers, etc. has been carried out.
The current situation is that the companies that own these have kept them. The root cause that cannot be solved is the internal electrode portion of the transformer / capacitor or the like, and it is extremely difficult to treat the iron core of the oil containing PCB.

That is, under the present circumstances, all of them are dangerous work such as shredding in the air, crushing upon cooling, press deformation, etc., which may cause the PCB to be scattered by the operator, and subsequent condensation of the gasified PCB. It has an extraction by a distillation tower, an extraction by a distillation apparatus, and a PCB vaporization step, and there is a risk of escaping the PCB gas and affecting human health and the environment.

In view of the above-mentioned difficulties in processing, there has been proposed a proposal which makes it possible to wash and remove harmful substances safely without polluting the working environment or directly holding or touching the workers. 2000-61410.

That is, as shown in FIG.
And placed in the washing tank 3. Supercritical carbon dioxide 4
The article 1 is washed by supplying the co-solvent 5 to the washing tank 3 and bringing the article into contact with the article 1. Thereby, the PCB contained in the article 1 is removed. If the article 1 has a high degree of sealing, the article 6 is crushed or broken by the device 6, and the supercritical carbon dioxide 4 easily enters the inside. After washing, washing tank 3
Contained in supercritical carbon dioxide 4 discharged from coal
The concentration of CB is detected by the detection unit 7, and the cleaning state is monitored. Further, the supercritical carbon dioxide 4 is guided to the separator 8 and cooled and reduced in pressure below the critical point, thereby returning to normal carbon dioxide and separated from PCB. This PCB is transported to the harmful substance treatment facility through the pipe 9. In the figure, 10 is a compression device for circulating supercritical fluid,
Reference numeral 11 denotes a pressure reducing valve, and 12 denotes a harmful substance outlet.

[0013] However, since the articles containing harmful substances are stored in a container and placed in the washing tank at the time of washing, the articles are safely processed without the operator directly grasping or contacting the articles. be able to. In addition, since the removed harmful substances are collected without contacting the outside air outside the cleaning tank, the environment is not polluted.

Further, since the articles are physically destroyed in the cleaning tank, no harmful substances trapped inside are scattered and adhere to workers, and the environment is not polluted. It can be processed safely, and is particularly suitable for cleaning electric components such as transformers and ballasts having a high degree of sealing.

[0015]

According to the means shown in FIG. 4, a transformer or the like is destroyed, crushed and washed in the washing tank 2 and harmful substances removed therefrom are removed from the outside of the washing tank. Although it is highly appreciated that the above-mentioned risk of PCB splatter and PCB gas escape is prevented because it is not brought into contact with the pressure vessel, the destruction device is installed in the cleaning tank 2 (which is very difficult) of the pressure-resistant container. The apparatus 14 must be provided with an excessive load on equipment (equipment immersed in supercritical fluid must deal with deterioration of equipment and elution of lubricating oil).

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is not to be bound by the unrealistic ideal of performing all processes in a closed circulation system of a supercritical fluid. Detoxification treatment of PCB-containing insulating oil such as transformers, which can realize each processing step within the range that can be realistically achieved and can effectively utilize it to achieve the same effect as the above-mentioned ideal. It is to provide a method.

[0017]

A PC such as a transformer according to the present invention.
In the method for detoxifying the B-containing insulating oil, a transformer / transformer, etc., after removing the PCB-containing insulating oil, is installed in a water tank provided in a sealed chamber completely shut off from the outside air by using a crushing machine previously arranged in the water tank. After crushing in water to a predetermined size, the crushed pieces are washed by ultrasonic cleaning with addition of active solvent and addition of heating convection, and at the same time, copper and iron piece metal / insulator and chip-like wood / paper / fiber are float-selected and overflowed. The first part of the water tank treatment, in which the surface oil of the oil layer is recovered through a separation filter and the water is reused, and the washed copper, iron flake metal and insulator obtained in the above step are recycled. Chip wood, paper, and still impregnated with PCB
The fiber is heated to lower the density by heating the filled supercritical fluid CO ₂ from a filling port provided at an appropriate part of the vertical supercritical fluid circulation pipe at the lower part of one vertical pipe of the supercritical fluid circulation pipe. A superheater consisting of a contact device, a reboiler and a super heater consisting of an external contact device for increasing the density gradient by further heating is placed above the sample boiler, and a sample filling container consisting of a mesh body and a fluid A cooler consisting of an external contact device for cooling and increasing the density is arranged, and a supercooler consisting of an external contact device is further arranged at the lower part of the pipeline to promote the densification of the lower part of the pipeline, The solvent CO _{2 is used} as a driving force based on the density difference generated by the heating of the reboiler and the superheater and the cooler in the other longitudinal path and the supercooler in the bottom.
Is automatically circulated inside the vessel, and complete extraction is performed by repeated contact of the same solvent with the sample by the circulation, and extraction is performed using an extraction system using a supercritical fluid CO ₂ as a solvent which is taken out from an appropriate portion of the above-mentioned conduit. A second step of processing to recover a small amount of impregnated insulating oil, and to recycle wood, paper, and fiber;
The oil recovered in the first and second steps is combined to form the second
Into the supercritical fluid circuit in the process together with the oxidant,
By repeating the supercritical water oxidation reaction, the water is decomposed into water, carbon dioxide, and hydrochloric acid, and the water is recycled to the water tank, and the carbon dioxide is recycled to the extraction system.

[0018]

[Function] In underwater crushing, consideration must be given to the effect of equipment on water, but this problem is an item that can be easily cleared, and there is no difficulty.

The water tank itself is not a heavy burden, but the crushing and washing processes can be performed with ordinary indoor facilities. Realistic.

The processed material handled by the pressure-resistant supercritical fluid device is only paper / wood chipped and recovered PCB oil, and there is no need to increase the size at all.

Here, a practical and practical processing method is provided.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The outline of the method of the present invention is shown in FIG.

In the figure, reference numeral 13 denotes a water tank provided in a sealed room completely shut off from outside air of a double structure house, for example.
A crusher 14 (preferably a two-stage crusher) for crushing a transformer / transformer after removing the B-containing insulating oil, and a mesh conveyor belt 15 (metal or the like) connected to the crusher 14 as a light / heavy material sorting path Of the weight crushed body falls on the lower conveyor belt 16 from the mesh), and further, the belt 1
An inclined water channel 17 for taking out of the tank connected to 5 and 16 is housed.

For the above-mentioned belt 15 and the water channel 17, an ultrasonic cleaning device to which an active solvent is added and heating for forming upward convection (P
(A low temperature that does not lead to CB gasification) (not shown).

Thus, the crushed material is washed while passing through the belts 15 and 16 and the water channel 17 and separated by weight difference sorting (the copper and iron piece metal and the insulator 18 are settled, and
Paper / fibers 19 rise and float).

Further, the overflow section 2 at the upper edge of the tank 13
At 0, only oily water is led through the mesh plate 21 and is separated into water and oil through the oil separator 22.

The oil separator 22 is also installed in the collecting section 18a, 19a of the copper or the like 18, the chip-like tree 19 or the like. The copper 18 and the like 18 collected by the collection unit 18a are recycled.

The PCB-containing oil 24 from the oil separator 22 is re-charged to the oil tank 23, and the water 25 is re-charged to the tank 13 via the pump 26.

Here, it is assumed that the work is performed indoors by being completely shut off from underwater crushing and the outside air, so that PCB scattering and P
A cleaning system outside the closed circulating system of the supercritical fluid, which prevents the escape of the CB gas and the escape of the PCB gas, is realized.

The collected chips 19 are fed into a supercritical fluid extraction system 27.

The extraction system 27 is shown in detail in FIG.

The present system 27 is a high-performance extraction system disclosed in Japanese Patent No. 3079157, in which the above-mentioned insulating oil is completely extracted using CO ₂ as a solvent.

In the figure, reference numeral 28 denotes a small cabinet which accommodates a supercritical fluid circulation high-pressure pipe 29 having a vertical configuration, and main equipment is installed in the cabinet 28. First, a reboiler 3 of an external contact device is provided below one of the vertical paths 29a.
0, a super-heater 31 of the external contact device is also arranged above, and each heating body 30a, 31a is a temperature controller 3
2, 33.

Further, thermocouples 34 and 35 are attached to the reboiler 30 and the superheater 31, respectively. An electric sensor 3 for detecting the system pressure is provided at the upper part of the pipe line 29.
6 is arranged and monitored by a measuring instrument 37;
The safe operating pressure is controlled by a rupturable plate 38 disposed nearby.

A sample filling container 39 (extraction column) made of a mesh body made of stainless steel or the like that withstands high temperature and high pressure is arranged in the middle of the other vertical path 29b. A thermocouple 40 is provided in the extraction column. A cooler 42 composed of an external contact device connected to the cooling unit 41 is disposed above the extraction column. Further, a supercooler 44 composed of an external contact device connected to the cooling unit 43 is disposed below the pipeline 29 located in front of the reboiler 30.

An analysis tube 47 having sampling valves 45 and 46 is arranged below the pipe line 29. In the illustrated example, a solvent filling port 48 is provided below the extraction column, and a thermocouple 49 is provided downstream. The above-mentioned system can give a calculated flow rate to the pipe line 29 by controlling the heating and cooling by using the temperature and pressure data from the various instruments described above by the computer 50. It is desirable that the computer 50 has a keyboard, a monitor, and an instruction device, because the progress of displaying and extracting input data can be grasped.

In this system, CO ₂ is used as a solvent, and an insulating oil impregnated substance such as floc is stored in a sample filling container 39.

Thus, the ultimate insulating oil extraction is achieved by repeated pairing of sample (flock) with the same solvent by automatic circulation of the solvent CO ₂ .

Here, CO ₂ was used as the solvent for the following reason.

That is, the characteristics of the solvent are determined by the thermal motion of the molecule and what kind of intermolecular force is acting. The attractive forces acting between the molecules are the cloning force, the charge transfer force, the hydrogen bonding force, and
Classified as vander Waals power. Furthermore, van der Waals
The force is the dispersion force based on the instantaneous charge distribution bias due to the electron motion, and the orientation force acting between the permanent dipole based on the uneven distribution of electrons in the molecule and the induced dipole caused by the permanent dipole. To the induced force acting on the CO ₂ is a non-polar substance whose only dispersing power is important. It is a gas at room temperature and normal pressure having a critical temperature of around 309.2 K and at room temperature and normal pressure. It dissolves lipophilic substances, but hardly dissolves highly polar substances.

However, it is because the harmless CO ₂ is optimally used as the solvent for the PCB-containing insulating oil to be extracted.

The extraction step is completed by removing the insulating oil 51 from the sampling valve 46 by extraction under reduced pressure.

The repeated regenerating action of the same solvent achieves the ultimate complete extraction.

The extraction degree is thoroughly checked by sampling over time.

The oil 51 is collected in an oil tank 52 and
The chip-like tree 19 'from which the B oil has been extracted and removed is provided for recycling.

In the oil tank 52, oil from the oil tank 23 as well as oil extracted from the transformer / transformer in this section is collected and fed into the supercritical water oxidation reaction system 53.

The system 53 is shown in detail in FIG.

This uses the same supercritical fluid circulation high-pressure line 29 as the above-mentioned extraction system 27, and the same components as those in FIG.

The oil tank 52 is connected to a supercritical water oxidation system 53 via a pipe 54, and 55 is a tank for an oxidizing agent such as hydrogen peroxide which joins the oil in the middle of the pipe 34; Is a pump disposed before the system 53 for pumping the oil and the water solvent.

A take-out port 57 is provided at a predetermined portion of the pipe line 29, and check and take-out are performed.

Since the supercritical hydroxylation reaction in the present invention is performed not in a one-way but in a circulation path, the chance of contact with the supercritical water is very high, and a complete reaction can be expected.

The time check at the outlet 57 ensures complete processing.

In the supercritical high-temperature and high-pressure state, 10 to 10
100 times as many water molecules are dissociated into ions.

Therefore, the water itself is given an acid catalyst and an alkali catalyst effect, and the chlorine-containing organic substance is dechlorinated in an alkaline state. Is dechlorinated, hydrogen peroxide and the like are added and reacted in a short time, the organic chlorine compound is completely decomposed, and the PCB-containing oil is decomposed into water, carbon dioxide and hydrochloric acid as is well known.

In FIG. 1, the water 25 is recycled to the water tank 13, and the carbon dioxide 58 is supplied to the extraction system 27.

Hydrochloric acid is used as the acid. After all, there is no harmful substance out of the system.

[0057]

As described above, since the method of the present invention is constituted, PCB separation and complete detoxification can be carried out without imposing any unreasonable design burden on processing with a supercritical fluid having absolute reliability. It is realized while achieving the prevention of separation and the escape of PCB gas, which is extremely significant in the field. In addition, all of the processing products are completely utilized and no harm is caused.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of the method of the present invention.

FIG. 2 is a detailed view of the extraction system of the present invention.

FIG. 3 is a detailed view of the supercritical water oxidation system of the present invention.

FIG. 4 is an explanatory diagram of a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1; Article 2; Container 3; Cleaning tank 4; Carbon dioxide 5; Cosolvent 6; Device 7; Detector 8; Separator 9; Piping 10; Outlet 13; Water tank 14; Crusher 15, 16; Conveyor belt 17; Inclined waterway 18; Copper / iron metal / insulators 18a, 19a; Recovery unit 19; Oil separator 23; Oil tank 24; PCB-containing oil 25; Water 26; Pump 27; Supercritical fluid extraction system 28; Cabinet 29; Heating body 31; superheater 32, 33; temperature controller 34, 35; thermocouple 36; electric sensor 37; Measuring instrument 38; rupturable plate 39; sample filling container 40; thermocouple 41; cooling unit 42; cooler 43; cooling unit 44; supercooler 45, 46; valve 47; analyzing tube 48; 50; computer 51; insulating oil 52; oil tank 53; supercritical water oxidation reaction system 54; line 55; tank 56; pump 57; outlet 58; carbon dioxide

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B01J 3/04 B02C 23/08 Z 4D071 B02C 23/08 23/36 4H006 23/36 B03B 5/28 Z B03B 5/28 7/00 7/00 9/06 9/06 B08B 3/08 A B08B 3/08 3/10 Z 3/10 3/12 A 3/12 3/14 3/14 C07B 35/06 B09B 3 / 00 37/06 C07B 35/06 C07C 25/18 37/06 B09B 5/00 ZABZ C07C 25/18 3/00 Z 304Z F term (reference) 2E191 BA13 BB00 BC01 BD11 3B201 AA48 AB14 AB37 BB04 BB82 BB92 BB95 CB15 CD22 4D004 AA50 AB06 AC05 BA05 BA09 CA04 CA10 CA22 CA34 CA39 CA40 CB05 CB13 CB32 CC04 CC11 4D056 AB13 AC24 BA11 BA16 CA18 CA20 CA21 CA22 CA31 4D067 DD02 DD07 DD18 DD19 GA20 GB05 4D071 AA41 AB06 AB14 AB23 DA15 AC30 BC30 BC05 ABC 5 BE32 EA22

Claims (1)

[Claims] In a water tank provided in a sealed chamber completely insulated from outside air, a transformer, a transformer, etc., after extracting insulating oil containing PCB is crushed underwater to a predetermined size by a crushing machine previously provided in the water tank. After that, the crushed pieces are washed by ultrasonic cleaning with addition of an active solvent and addition of heating convection, and at the same time, copper and iron piece metals and insulators are separated from chips, wood, paper and fibers by floating separation, and the oily surface film water of overflow is separated. The oil content is recovered through a filter, and the water is reused for the first time in a water tank treatment. The washed copper, iron flake metal and insulator obtained in the above step are recycled and the PCB is still recycled. The impregnated chip-shaped wood, paper, and fiber are filled with supercritical fluid CO ₂ to be filled from a filling port provided at an appropriate part of the vertical supercritical fluid circulation pipe at a lower part of the pipe. Outside where the density is reduced by heating A superheater consisting of a contact device, a reboiler and an external contact device for increasing the density gradient by further heating is arranged above the reboiler, and a sample filling container consisting of a mesh body and a fluid A cooler consisting of an external contact device for cooling and increasing the density is arranged, and a supercooler consisting of an external contact device is further arranged at the lower part of the pipeline to promote the densification of the lower part of the pipeline, The solvent CO ₂ is automatically circulated inside the vessel as a driving force using the density difference generated by the heating of the reboiler and the superheater and the cooler in the other vertical path and the supercooler at the bottom, and the same solvent is circulated by the circulation. No complete extraction with repeated pairs sample contact supercritical fluid CO ₂ is taken out from the appropriate site of the pipe extraction process in the extraction system as a solvent traces impregnated insulating oil was recovered Wood, paper, and fibers are combined with the second step of recycling and the oil recovered in the first and second steps, and are fed into the supercritical fluid circulation path in the second step together with an oxidizing agent, By repeating the critical hydroxylation reaction, the water is decomposed into water, carbon dioxide, and hydrochloric acid, and the water is contained in the water tank, and the carbon dioxide is recycled in the extraction system. A method for detoxifying the entire amount of PCB-containing insulating oil such as transformers.